Just got my Amstrad out after a year, grey screen, no beeps.

[jasonorme666]

So I just dug my Amstrad cpc 464 out. It was only a couple of years ago since I last used it and wanted to show my 2 year old daughter some old games.
On plugging it in I'm greeted with a grey screen with black borders. There is a red light on the keyboard, no beeps when holding delete, but the fast forward, rewind etc work.. just not play. No text on the screen either.
I blasted some compressed air into the ports to give em a clean, still no luck.


I'm at a total loss.


Is it safe for me to open up the keyboard and fiddle with the connections?..  I wouldn't dare open up the monitor.

[ukmarkh]

So I just dug my Amstrad cpc 464 out. It was only a couple of years ago since I last used it and wanted to show my 2 year old daughter some old games.
On plugging it in I'm greeted with a grey screen with black borders. There is a red light on the keyboard, no beeps when holding delete, but the fast forward, rewind etc work.. just not play. No text on the screen either.
I blasted some compressed air into the ports to give em a clean, still no luck.


I'm at a total loss.


Is it safe for me to open up the keyboard and fiddle with the connections?..  I wouldn't dare open up the monitor.

I know this will probably sound weird, but I’ve recovered from this screen by doing two things on separate occasions. 1. The on/off switch isn’t fully engaging and so not switching on, so you either should try replacing or taking it apart and cleaning. 2. I had a rusty keyboard membrane that caused this, found a replacement on eBay and then it worked fine. If this doesn’t fix your issue, then you should try to replace the removable chips such as ROM chip, and then CPU, there’s three or four in total, but one at a time, otherwise it could prove expensive. Obviously if you have access to another CPC, then you can swap things around until you find the issue, but it’s not as easy as people might suggest, trial and error. Good luck plenty of people on here will help.


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[gerald]

On plugging it in I'm greeted with a grey screen with black borders.

That the usual sign of RAM issue.

Is it safe for me to open up the keyboard and fiddle with the connections

Yes, you can open it, an there is no need for opening the monitor.
While it is open, please note the revision of the motherboard (http://www.cpcwiki.eu/index.php/Mainboard_Versions#CPC464_version_1_.28original.29)
You should find 2 chip on socket that may need to be refitted.
As a first go, just push them does and re-test the CPC.
If it's not better, remove them from they socket and refit them (without bending any pins), re-test the CPC.
If it's sill no good, the ram are likely the culprit and you will have to do some chip replacement.

[jasonorme666]

CPC464 version 2
Board: PT NO Z70200, MC0002D, Copyright 1984

I've pressed all the chips down, still nothing
Which ones do I have to try and remove / refit?

Thanks for the help guys.

[kailokyra]

If you put your finger on top of the ram chip when the computer is running, one (or multiple) might be really hot. Desolder it, replace it with a new one and voila !


Now, if they're all at the same temperature, you can either probe them to see if a bit is stuck and never moves, or just desolder and change all of them at once. That chip is really cheap to get from China on aliexpress for a bundle of 10 usually

[jasonorme666]

They all seem to be running at the same temp.. (well. none of them even feel warm).

[gerald]

Do you have a multimeter ?
If so can you check that you have 5V on the main board ?

[jasonorme666]

I do, but I'm a bit clueless about how to use it.


But the Keyboard does make that nice pop sound when turning it on, and a change of pitch can be heard when moving the volume up and down.

[jasonorme666]

I have removed and refitted the 2 removable chips. They looked alright, pins looked clean but sadly this didn't change anything.
If it was any of the other chips I'm rather screwed as I'm no good at soldering.


I may have to buy a new one at this rate, but there are so many untested ones on eBay, and any that are tested are over double the price and come with the monitor that I don't need.


Are random deaths common with these computers? How do you guys go about preventing it?.

[Bryce]

There's no way of really avoiding such failures, other than the obvious things like "don't store it in a damp cellar" etc. It's old electronics, these things break. The CPC isn't particularly prone to failure any more than any old computer, however, there are much more unreliable 8-bit computers out there (looking at you C64 Breadbin!).

What people do: They remove the PCB from the computer, pack it with lots of protection in a box. Send a PM to me or someone else known to repair 8-bit computers and say, "Here Bryce, can you fix this for me" and then head off to the post office.

Bryce.

[jasonorme666]

I think I'd better send you a PM then before this Amstrad ends up flung through the window....   I even had the Mrs working on it last night, I don't think she wanted to, but could see me getting greyer and more bald as the day went on.

[ukmarkh]

There's no way of really avoiding such failures, other than the obvious things like "don't store it in a damp cellar" etc. It's old electronics, these things break. The CPC isn't particularly prone to failure any more than any old computer, however, there are much more unreliable 8-bit computers out there (looking at you C64 Breadbin!).

What people do: They remove the PCB from the computer, pack it with lots of protection in a box. Send a PM to me or someone else known to repair 8-bit computers and say, "Here Bryce, can you fix this for me" and then head off to the post office.

Bryce.

If he does send to you, would be great if you documented the process of troubleshooting/fixing these old CPC’s, maybe a video. I have two CPC’s including a new one I just purchased with this problem.

Thx


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[Bryce]

I don't really do videos, but I usually document repairs here on the Forum. At least when they turn out to be something unusual or someone previously repaired it with a hammer/fork/nail cutters/plastic putty/all of the above etc.

Bryce.

[jasonorme666]

Well I just snapped one of the legs off the chips, so after everything I think I'm going to give up and buy a working one I've seen,. The Mrs just said, "Look, it's a 2 hour drive but if it means I don't have to hear about this fucking Amstrad again, I will go fetch it". 

[ukmarkh]

Well I just snapped one of the legs off the chips, so after everything I think I'm going to give up and buy a working one I've seen,. The Mrs just said, "Look, it's a 2 hour drive but if it means I don't have to hear about this fucking Amstrad again, I will go fetch it". 

Good gal Proper ‘un you’ve got there. Seriously though, you could always send it to me, just the board to keep costs down and I will get to the bottom of it. I like a good challenge. I’m in Solihull, West Midlands if it helps.


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